Restore KotlinCompilerVersion.IS_PRE_RELEASE

This commit is a slightly modified revert of 4f29c113.
IS_PRE_RELEASE allows to make LATEST_STABLE version behave as
experimental when this flag is set to true.
The general goal is to prepare fix of KT-62058; after this commit
one can do it by changing IS_PRE_RELEASE flag to true.
The fix of KT-62058 is planned to be done during bootstrapping.
This preparation and the future fix are parts of umbrella KT-61951.

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryLatestStable/library/a.kt

@@ -0,0 +1,5 @@
+package a
+
+class A
+
+fun A.foo() = ""

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryLatestStable/output.txt

@@ -0,0 +1 @@
+OK

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryLatestStable/source.kt

@@ -0,0 +1,7 @@
+package usage
+
+import a.*
+
+fun baz(param: A) {
+    param.foo()
+}

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryStableLanguageVersion/library/a.kt

@@ -0,0 +1,5 @@
+package a
+
+class A
+
+fun foo() = ""

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryStableLanguageVersion/output.txt

@@ -0,0 +1 @@
+OK

compiler/testData/compileKotlinAgainstCustomBinaries/preReleaseCompilerAgainstPreReleaseLibraryStableLanguageVersion/source.kt

@@ -0,0 +1,8 @@
+package usage
+
+import a.*
+
+fun baz(param: A): A {
+    foo()
+    return param
+}